1. Field of the Invention
The present invention is directed generally to microtechnology/nanotechnology and, more particularly, to fabricating biocompatible scaffolds with highly-ordered arrays of high-aspect ratio conduits and to fabricating nano-scale templates with highly-ordered arrays of high-aspect ratio conduits.
2. Description of the Related Art
Conventional machining technologies have long been used to manufacture components for a variety of applications. However, conventional techniques are limited to certain types of materials (e.g., metal) and face fundamental limitations in the size of the components.
For example, it is desirable in some applications to have a structure that contains pores or conduits with a very small diameter. Many applications that require small pore size also require a relatively long pore length. Known techniques for creating such high-aspect ratio pores are not suitable for a number of reasons. Mechanical drilling is not gentle enough to fabricate structures with thin walls and cannot be used to achieve holes with a diameter <100 micrometers (μm).
Photolithography is not capable of producing features having a length exceeding 2 μm. Standard photolithographic techniques, used for patterning semiconductor devices, cannot produce 2 μm high-aspect ratio pores. The maximum achievable pore length of a standard photolithographic patterning is typically <0.1 millimeters (mm), and is limited by the maximum achievable thickness of photo resist. Alternatively, LIGA is a German lithography process utilizing synchrontron radiation that may be capable of generating higher aspect ratio pores, but is cost prohibitive. This is particularly important if the nano-scale device is disposable.
Laser drilling is generally not compatible with bio-polymer gels, which may be as much as 97% water. In addition, it is difficult to achieve high intensity at a spot size <100 μm with laser drilling. Dye extrusion is also an incompatible process for bio-polymer gels.
Accordingly, it can be appreciated that there is a significant need for a process compatible with materials and capable of patterning high-aspect ratio features ranging from the nanometer to millimeter scale. The present invention provides this, and other advantages as will be apparent from the following detailed description and accompanying figures.